OK, it could have been a better year. I should be showing you the spiffy images I took at the Iowa Star Party, but alas -- I did not attend. I had a nasty head cold, complete with cough and a nose that would not stop running. I thought it better to stay home and not give the virus a chance to claim more victims. The weather would have been two beautiful clear nights; I had plans to do two all-nighters despite knowing that wouldn't have done anything good for my health.
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| My 2026 imaging buddy, the rhinovirus |
Recall that in May there was a big assemblage of Minnesota Astronomical Society imagers planned at Lac qui Parle state park, a wonderful dark sky site. I also missed that because of a head cold.
In other words, I got blitzed at both ends of my imaging year by lousy timing. I will quote Zathras (a character on the TV series Babylon 5) who was lamenting his lot in life and its eventual sorry end but somehow managed to salvage one bit of comfort observing, "... but, at least there is symmetry!" My hope is that El Niño will summon up a gloriously warm and clear November new moon and I'll get one last shot at imaging before winter shuts me down. Maybe that would restore a little asymmetry to my imaging year.
I held onto it because it's an excellent little scope and it has taken some nice images for me: M45, M33, the Iris Nebula, and NGC 1528. (These are from my pre-PixInsight period, and will probably will look markedly better if I reprocess them. See this earlier post about reprocessing old data.) What I would like to do prior to selling the scope is take a new image to demonstrate to potential buyers exactly what it can do now using modern image processing.
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I'm thinking about selling my Astro-Tech AT65EDQ, mainly because I haven't used it for years.
In case you don't know, the AT65 is a 65 mm f/6.5 objective in a triplet - singlet quad arrangement. An apochromat, it has a 44 mm flat field, essentially perfect for APS-C sensors. It was offered for sale from 2011 to 2015 as an affordable, entry level apochromat for astrophotography. Supply chain and quality control issues quickly threatened to drive up the AT65's price, and Astro-Tech decided it could no longer be a competitive product. It was therefore discontinued.
It's production lifetime was plagued by quality control issues. Pinched optics were perhaps the most common issue. Despite this a certain mystique has developed around the scope and 15 years removed from its introduction it still trades briskly.
My particular AT65 is nice and flat on my APS-C sensors and I see little evidence of any pinching. So far as I know, I am the scope's third owner. My earliest posted images using this scope come from autumn of 2013, so with two previous owners, I expect this is an early model, perhaps from the first year of production.
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| A pristine AT65EDQ |
In preparing for that new image I was reminded of the AT65's focuser problem. It uses a compression ring inside the rotation collar to accept 2" nosepieces. This means that the camera is not hard-connected to the focuser, potentially allowing shifting as the mount tracks and possible non-orthogonality. In 2013 I looked into replacing the focuser, but that was going to cost far more than the telescope itself. So the little scope fell out of the lineup, replaced by my TV-102 and later the FSQ-106.
When Pegasus updated their FocusCube to version 3 I bumped my version 2 from the FSQ-106 to the AT65; a few nights ago I decided to finally do its NINA autofocus calibration. That went well, so the scope moved up a notch in my esteem as it now supported automated imaging.
The last issue to fix was the nosepiece connection, so I went out on the internet and found a post on CloudyNights said that if one removed the rotation collar the drawtube threads (M54) could be accessed. I would need to buy an adapter that had M54 male on the scope side and M48 male on the camera side. That adapter is something of a rare bird, but I found it available on Amazon and placed the order.
Unfortunately the new M54 adapter did not work. The CN post was either mistaken or referred to an AT65 that had different hardware (which is distinctly possible) so I got out my digital caliper and thread pitch gauge. It turns out the drawtube is M52x0.75, an even rarer bird. One was found on eBay, so that's on order now, but due in late November. So it's unlikely that I'll get that modern image made this year.
More about that when it arrives.
WARNING: If you contemplate removing the AT65's rotator, be aware that it acts as a stop for inward focuser travel. Without that stop, you run the risk of racking in so far that the tube makes contact with the field flattener or its supporting hardware. This would be a Very Bad Thing. If you plant to use motorized focusing, set up your focus motor to work as a stop; if manually focusing, be careful.
Incidentally, if you are using an AT65 and don't have the documentation for it, look here.
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The quandary will be if the test image turns out as wonderful as I hope. As I get older, I'll be downsizing; the FSQ will be sold along with the G11, and with luck and good health I'll use the proceeds to buy a smaller and lighter mount and continue imaging with a smaller refractor. Why not the AT65?
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Next time, the November new moon... will it be unseasonably warm, or will it be winter?
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